1. Field of the Preferred Embodiment
This invention pertains generally to wearable articles for the feet, and more particularly to shoes having a resilient sole having a shock-absorbing platform and heel cavity, possibly with air movement through the sole.
2. Description of the Related Art
Conventional shoes are often uncomfortable due to a lack of resiliency in the sole, particularly in the heel area. Inflexible heels do not promote walking or standing for long periods of time because they lack substantial cushioning and resiliency to accommodate pressure exerted on a wearer's feet. This lack of cushioning causes undue pressure and force-of-impact to be felt up into the knees, spine, and various other joints. Compressible heels having recessed chambers and springs in some cases are not new. None of the prior art successfully cushions a wearer's feet to the extent of the instant invention. Conventional shoes also fail to provide a flow of fresh air through the inside of the sole around an individual's feet.
For instance, U.S. Pat. No. 1,471,042 to Lewis (1923) discloses a shoe that uses coil springs internal to the defined heel. Lewis' shoe, however, uses metal plates (circular metal disks) above and below the coil spring(s) to help distribute pressure and also has no real cavity or resiliency in the sole. U.S. Pat. No. 2,257,482 to Resko (1941) discloses using lugs to better seat the coil spring in the defined heel, but still uses a metal reinforcing plate between the upper and lower soles to distribute pressure, also lacking resiliency in the heel. U.S. Pat. No. 3,886,674 to Pavia (1975) discloses a shoe having a plurality of springs in a non-defined, open heel. Because the springs are not enclosed, there is no sidewall surrounding the heel area. Further, there is a metal plate above the springs in the heelstrike area, so the wearer's foot still strikes against a hard surface.
Another family of prior art patents has addressed heel/cavity design. For instance, U.S. Pat. Nos. to Bunns 1,502,087, Denk 2,299,009, Carroll 6,622,401, and Dixon 5,544,431, and U.S. patent application Ser. No. 10/022,477 to Wu disclose cavities in well defined heels. Lombardino U.S. Pat. No. 5,743,028 discloses a blended heel, but lacks a platform connected to a substantially inelastic sidewall by virtue of a discrete deformable area. Consequently, movement is limited to a hinge-like articulating movement in the heelstrike area.
Still other patents, for instance U.S. Pat. No. 7,159,338 to LeVert et al., disclose a spring cushioned shoe with an inner vacuity connected by a passageway to an opening on the exterior of the shoe. The passageway opening described in the '338 patent, however, is both an inlet and an outlet and thus undesirably allows fluids and other unwanted debris into the shoe to the discomfort of the wearer and associated problems from water and mold developing within the shoe. Similarly, U.S. Pat. No. 1,069,001 to Guy discloses a cushioned sole and heel that allows air or other fluids in through a check valve to serve as the cushioning medium.
U.S. Pat. No. 5,505,010 to Fukuoka discloses a shoe having a resilient heel having a circular convexity (2b) and a ring-shape groove (2c) surrounding the convexity. While in this structure the convexity is capable of moving independently of other parts of the sole, Fukuoka requires a ring-shape groove (2c) of varying thickness, which tends to create an area of weakness, prone to breakage and malfunction. Thus, a needs exists for an improved ventilated and resilient shoe that overcomes the numerous limitations and problems in the prior art.